The invention relates to devices which permit a ladder to stand level on an uneven surface.
Various devices are known to assist in supporting a ladder on an uneven or sloped surface. Hodson U.S. Pat. No. 4,456,095 issued Jun. 26, 1984 discloses one such device. It provides a frame for attachment to the legs of the ladder, with a support arc which is adjustable through the frame to raise or lower the feet of the support arc to accommodate irregularities in the supporting surface. This device however does not adapt to ladders of different widths. Hodson U.S. Pat. No. 4,591,023 issued May 27, 1986 discloses a levelling device for ladders which may be used on ladders of differing widths, but it is difficult to adjust this device, since it is necessary to lift the ladder to unweight the lugs which grip the arcuate support bar in order to adjust the support bar. There is therefore a need for a ladder levelling device which is easily adjustable to different surfaces. There is further a need for a ladder levelling device is easily adjustable to different surfaces and which adapts to ladders of differing widths.
The invention therefore provides a device for supporting in a level manner on an uneven surface a ladder having parallel side rails joined by rungs, the device comprising: i) an arcuate support member provided at either end thereof with ground-engaging feet; and ii) two opposed bracket means for adjustably and releasably securing the side rails of the ladder to the arcuate support member; wherein the bracket means each comprise: iii) securement means adapted for attaching to a side rail of a ladder; iv) a locking plate provided with an aperture for slidably receiving the arcuate support member, pivotally mounted in the securement means for pivotal movement between a first binding and locking position and a second releasing and adjusting position; and v) means for biasing the locking plates to bind against the arcuate support member and thereby secure the bracket member against movement relative to the arcuate support member in the biasing direction when the locking plate is in the locking position.
In a further aspect, the invention provides a device for supporting in a level manner on an uneven surface a ladder having parallel side rails joined by rungs, the device comprising: i) an arcuate support member provided at either end thereof with ground-engaging feet; and ii) opposed bracket means for adjustably and releasably securing the side rails of the ladder to the arcuate support member; wherein the bracket means each comprise: iii) a cylindrical housing releasably held in said bracket means and provided with apertures to receive said arcuate support member in a direction perpendicular to the central axis of said cylindrical housing; iv) a locking plate extending through and pivotally mounted in the cylindrical housing; and v) means for biasing the locking plates to bind against the arcuate support member and thereby secure the bracket member against movement relative to the arcuate support member in the biassing direction.